Behavior of Post-Installed Anchors Tested by Stepwise Increasing Cyclic Load Protocols

摘要

Cyclic loads are a characteristic feature of actions acting on structures and anchorages during earthquakes. For this reason, seismic qualification of post-installed concrete anchors according to the internationally recognized American Concrete Institute (ACI) standards ACI 355.2 and 355.4 are based on cyclic load tests. The protocols for these cyclic load tests, however, have limited scientific basis. Therefore, in the present paper, newly developed test protocols with stepwise increasing load amplitudes are used to more realistically evaluate anchor seismic performance. The study focuses on the load-displacement behavior of common anchor types installed in cracked concrete and subjected to both cyclic tension and cyclic shear actions. The results confirmed robust behavior for anchors loaded in cyclic tension even in the presence of crack widths in the anchorage material larger than currently required by ACI 355. In addition, the critical influence of low cycle fatigue on the performance of anchors loaded in cyclic shear is demonstrated.